What event prompts an update to the forwarding table information for a route with multiple physical next hops?

The correct choice highlights that the forwarding table information must be updated when a new physical next hop is added to the next-hop set for a route with multiple physical next hops. This is crucial because the forwarding table, which dictates how packets are routed, needs to accurately reflect all available paths to a destination.

When a new next hop is introduced, the routing protocol updates the forwarding table to ensure that traffic can be effectively balanced across all available paths. This load balancing increases redundancy and improves overall network performance. By acknowledging the addition of new next hops, the routing system can make better-informed decisions for packet forwarding, optimizing the utilization of network resources.

This situation emphasizes how dynamic and adaptable routing protocols can respond to changes in the network topology, enhancing both reliability and efficiency in routing decisions. Other options do not hold the same relevance because they either denote configuration changes that do not directly affect the forwarding table or events that occur after the forwarding decisions have already been made.